A first order reaction has a specific reaction rate of 10-2 sec-1. How much time will it take for 20 g of the reactant to reduce to 5 g ?

Question

A first order reaction has a specific reaction rate of 10-2 sec-1. How much time will it take for 20 g of the reactant to reduce to 5 g ? (A) 138.6 sec (B) 346.5 sec (C) 693.0 sec (D) 238.6 sec

Tardigrade Admin · Accepted Answer

t 1 / 2=(0.693/10-2) second For the reduction of 20 g of reactant to 5 g, two t 1 / 2 is required. t =2 × (0.693/10-2) second =138.6 second

Q. A first order reaction has a specific reaction rate of $1 0^{- 2} se c^{- 1}$ . How much time will it take for $20 g$ of the reactant to reduce to $5 g$ ?

138.6 sec

346.5 sec

693.0 sec

238.6 sec

$t_{1/2} = \frac{0.693}{1 0 ^{- 2}}$ second

For the reduction of $20 g$ of reactant to $5 g$ , two $t_{1/2}$ is required.

$t = 2 \times \frac{0.693}{1 0 ^{- 2}}$ second

$= 138.6$ second

Q. A first order reaction has a specific reaction rate of 10−2sec−1. How much time will it take for 20g of the reactant to reduce to 5g ?